Bucketsmith's blog

An aggressive but risky strategy that I used a lot during a contest
By Bucketsmith, history, 12 months ago, In English

When working on easier problems(like Div1A or Div2B/C), If it took me 10 minutes to get no clues, I would rather jump to some random conclusions that SEEM reasonable. If it passed the examples, I would submit it immediately, spending no time proving my solution. I thought a problem placed at Div1A/Div2B/C couldn't be that hard and I should not waste my time any further. It works and fails from time to time, but more fails on recent contests.

I wonder if some of you guys thought the same way during a contest. Should I give up this strategy anymore?

  • Vote: I like it
  • +58
  • Vote: I do not like it

Comments Comments (9)
| Write comment?
»
12 months ago, # |
  Vote: I like it +8 Vote: I do not like it

on today's hello 2024 contest, i used similar way to solve A by observing if abs(a-b) is even or not

→ Reply
  • »
    »
    12 months ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    I thought of A this way: as long as there are any coins left in either wallet, one can choose to swap or not to make the non-empty wallet in their hand, So the game would definitely proceed a + b turns.

    on problem C, I thought the longest non-increasing subsequence is always the optimal answer which completely makes no sense. I wasted 30 minutes and 2 rejected submissions on it. Sigh.

    → Reply
»
12 months ago, # |
  Vote: I like it +15 Vote: I do not like it

Happened to me in Hello 2024. Problem B. I was reading the problem statement. Very big. I just randomly scrolled over to the sample testcases. I observed that the answer was based on the count of the symbols. .Without reading the problem, ran the code for the sample testcases, and submitted it. Lucky for me, passed the pretests too. Going to read the problem all over again and do it properly now tho lol.

→ Reply
  • »
    »
    12 months ago, # ^ |
      Vote: I like it +15 Vote: I do not like it

    Also, congrats on becoming grandmaster!

    → Reply
  • »
    »
    12 months ago, # ^ |
      Vote: I like it +10 Vote: I do not like it

    yes in 2nd, it was simply the absolute difference of plus and minus sign.

    → Reply
»
12 months ago, # |
  Vote: I like it +19 Vote: I do not like it

wish I have done this, took me time to solve B on today's hello 2024

→ Reply
»
12 months ago, # |
← Rev. 2   Vote: I like it +11 Vote: I do not like it

I also did similar thing on yesterday's contest, that I have thought the correct solution of pC but I can neither prove it or disprove it, and the implementation won't take too long, so I decide to just submit it. Even if it didn't pass, I can disprove my solution by WA, and focus on other possible solution. So I guess in this situation it is not a bad strategy. (though there is a drawback that you might got FST when the pretest is weak)

btw, I just realized that logical reasoning is not the only way to solve CP problem, you can guess, you can bruteforce pattern, etc..., thanks to the notorious Goodbye 2023 problem D

→ Reply
»
12 months ago, # |
  Vote: I like it +4 Vote: I do not like it

Yes, guessing the solution is often more efficient than confirming it. I guess that with more experience you can also filter out most blatantly wrong approaches so there's still some filter to it.

→ Reply
»
12 months ago, # |
  Vote: I like it 0 Vote: I do not like it

Some problems can be solved just by guessing.

Here is an example: https://codeforces.me/contest/1776/problem/I

→ Reply